From b98ad21287cf086278ec617db68a2c3ba9a97c40 Mon Sep 17 00:00:00 2001
From: NePank <nepank@serpack.de>
Date: Thu, 11 Dec 2025 16:04:41 +0100
Subject: [PATCH 1/3] FIXED  undefined behavior in style_to_font function.

---
 Cargo.toml         |  1 -
 src/backend/mod.rs | 22 ++++++++++++----------
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d99fc37..857f9ec 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,6 @@ plotters = { version = "0.3", default-features = false }
 plotters-backend = "0.3"
 iced_widget = { version = "0.14", features = ["canvas"] }
 iced_graphics = "0.14"
-once_cell = "1"
 
 [dev-dependencies]
 plotters = { version = "0.3", default-features = false, features = [
diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index cc5ad2a..e11ba33 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -14,7 +14,6 @@ use iced_widget::{
     text::Alignment,
     text::Shaping,
 };
-use once_cell::unsync::Lazy;
 use plotters_backend::{
     //FontTransform,
     BackendColor,
@@ -27,7 +26,7 @@ use plotters_backend::{
     FontStyle,
     text_anchor,
 };
-use std::collections::HashSet;
+use std::sync::{LazyLock, Mutex};
 
 /// The Iced drawing backend
 pub(crate) struct IcedChartBackend<'a, B> {
@@ -302,10 +301,9 @@ where
     }
 }
 
-#[allow(static_mut_refs)]
 fn style_to_font<S: BackendTextStyle>(style: &S) -> Font {
     // iced font family requires static str
-    static mut FONTS: Lazy<HashSet<String>> = Lazy::new(HashSet::new);
+    static FONTS: LazyLock<Mutex<Vec<&'static str>>> = LazyLock::new(|| Mutex::new(Vec::new()));
 
     Font {
         family: match style.family() {
@@ -313,13 +311,17 @@ fn style_to_font<S: BackendTextStyle>(style: &S) -> Font {
             FontFamily::SansSerif => font::Family::SansSerif,
             FontFamily::Monospace => font::Family::Monospace,
             FontFamily::Name(s) => {
-                let s = unsafe {
-                    if !FONTS.contains(s) {
-                        FONTS.insert(String::from(s));
+                if let Ok(mut vec_guard) = FONTS.lock() {
+                    if let Some(&s) = vec_guard.iter().find(|&&vec_str| vec_str == s) {
+                        font::Family::Name(s)
+                    } else {
+                        let leaked_str = &Box::leak(Box::new(String::from(s)))[..];
+                        vec_guard.push(&leaked_str);
+                        font::Family::Name(leaked_str)
                     }
-                    FONTS.get(s).unwrap().as_str()
-                };
-                font::Family::Name(s)
+                } else {
+                    font::Family::default()
+                }
             }
         },
         weight: match style.style() {

From 99aae0e6df7d4145e2ba89228ad2d3efb114d202 Mon Sep 17 00:00:00 2001
From: serpack <nepank@serpack.de>
Date: Thu, 11 Dec 2025 18:28:16 +0100
Subject: [PATCH 2/3] - changed vec to hashset - changed "if let some" to
 map_or_else

---
 src/backend/mod.rs | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index e11ba33..0e64fb9 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -26,6 +26,7 @@ use plotters_backend::{
     FontStyle,
     text_anchor,
 };
+use std::collections::HashSet;
 use std::sync::{LazyLock, Mutex};
 
 /// The Iced drawing backend
@@ -303,26 +304,25 @@ where
 
 fn style_to_font<S: BackendTextStyle>(style: &S) -> Font {
     // iced font family requires static str
-    static FONTS: LazyLock<Mutex<Vec<&'static str>>> = LazyLock::new(|| Mutex::new(Vec::new()));
+    static FONTS: LazyLock<Mutex<HashSet<&'static str>>> =
+        LazyLock::new(|| Mutex::new(HashSet::new()));
 
     Font {
         family: match style.family() {
             FontFamily::Serif => font::Family::Serif,
             FontFamily::SansSerif => font::Family::SansSerif,
             FontFamily::Monospace => font::Family::Monospace,
-            FontFamily::Name(s) => {
-                if let Ok(mut vec_guard) = FONTS.lock() {
-                    if let Some(&s) = vec_guard.iter().find(|&&vec_str| vec_str == s) {
-                        font::Family::Name(s)
-                    } else {
+            FontFamily::Name(s) => FONTS.lock().map_or_else(
+                |_| font::Family::default(),
+                |mut vec_guard| {
+                    if !vec_guard.contains(s) {
                         let leaked_str = &Box::leak(Box::new(String::from(s)))[..];
-                        vec_guard.push(&leaked_str);
-                        font::Family::Name(leaked_str)
+                        vec_guard.insert(&leaked_str);
                     }
-                } else {
-                    font::Family::default()
-                }
-            }
+
+                    font::Family::Name(vec_guard.get(s).unwrap())
+                },
+            ),
         },
         weight: match style.style() {
             FontStyle::Bold => font::Weight::Bold,

From 94b6ccd873978e96f99095c4e98b4b9d395718c3 Mon Sep 17 00:00:00 2001
From: serpack <nepank@serpack.de>
Date: Wed, 24 Dec 2025 21:36:56 +0100
Subject: [PATCH 3/3] leak string without box::leak

---
 src/backend/mod.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index 0e64fb9..5ee57a2 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -316,11 +316,10 @@ fn style_to_font<S: BackendTextStyle>(style: &S) -> Font {
                 |_| font::Family::default(),
                 |mut vec_guard| {
                     if !vec_guard.contains(s) {
-                        let leaked_str = &Box::leak(Box::new(String::from(s)))[..];
-                        vec_guard.insert(&leaked_str);
+                        vec_guard.insert(String::from(s).leak());
                     }
 
-                    font::Family::Name(vec_guard.get(s).unwrap())
+                    font::Family::Name(*vec_guard.get(s).unwrap())
                 },
             ),
         },